The invention relates to a switching relay having an armature spring and, more specifically, to a switching relay having an armature spring with a torsional web region and a tension rod.
Electromagnetic switching relays, such as those taught in EP 0 203 496 A2 and EP 0 480 908 B1, are known in a wide variety of embodiments and are used, for example, in automotive engineering. The conventional switching relay has a magnet coil with a magnet core and a yoke. The yoke extends along the outside of the magnet coil from a first end to a second end. At the second end, the yoke has yoke mandrels on which an armature plate pivotally rests. When current is applied to the magnet coil, a closed magnetic field is generated via the magnet core, the yoke, and the armature plate, that is returned to the magnet core. The magnetic field attracts the armature plate toward the magnet core.
A closed or open position is fixed as a function of the position of the armature plate. In the closed position a contact bridge connected to the armature plate connects two electrical terminals to each other. In the open position the contact bridge connected to the armature plate disconnects the two electrical terminals. An armature spring has a tension rod with which a tensile force is transmitted to the armature plate so that the armature plate can be pivoted from the closed position into the open position with low resistance from the armature spring. The tension rod is typically designed as an elongated narrow strip that can be bent with little force to allow for low force movement of the armature plate. The design of the tension rod in the form of an elongated narrow strip, however, requires relatively complex manufacturing and can easily be damaged.
Another example of an electromagnetic switching relay is taught in DE 199 20 742 A1. This switching relay comprises a basic member, a magnet system, and an armature spring. The magnet system has an armature formed with two lever portions that provide the support points for the armature spring. A further support point for the armature spring is located on a fixed portion of the switching relay. The armature may be adjusted by bending the fixed portion of the switching relay to adjust the position of a switching contact in respect to fixed terminals. Owing to unavoidable manufacturing tolerances, the distance between the switching contact and the fixed terminals does not exactly correspond to a desired value, but is subject to manufacturing-related variations. As a result, individual adjustment of the contact spacing is required in each case.
It is therefore desirable to develop an armature spring for a switching relay of mechanically stable and compact construction that transmits a tensile force to an armature plate so that the armature plate can be pivoted from a closed position into an open position with low resistance from the armature spring.
The invention relates to an armature for a switching relay having an armature plate and an armature spring. The armature plate is pivotally mounted on the switching relay between an open and closed position. The armature spring is attached to the switching relay by a suspension and has a spring contact region connected to the armature plate. A first web is attached to the spring contact region, and a tension rod is connected to the first web so that minimal torsional forces are transmitted to the tension rod when the armature plate pivots between the open position and the closed position.